Slay.the.spire.v2020.12.15.zip ... | File-

Do not open it.
Instead:

The naming pattern Slay.The.Spire.v2020.12.15.zip strongly matches unofficial releases from warez groups or unauthorized archive sites. File- Slay.The.Spire.v2020.12.15.zip ...

v2020.12.15 suggests a repack from late 2020, likely bypassing DRM or copying the game without a legal license. Do not open it